Step 117: Another Project by Arcticpenguin

Step 61: BNAE or French Recess

[[br]]Also called BNAE NFL22-070 after its Bureau de Normalisation de l'Aeronautique et de l'Espace standard number. Possibly a security screw drive system. Easily confused with a JIS or Frearson recess screw but with driver blades are modified into two step diameters.[[br]]